In general, in construction machinery, such as an excavator, fuel efficiency is considerably different according to an operation pattern, such as a manipulation habit, of an operator. Especially, the construction machinery performs an operation over a long time, and the amount of fuel consumed of an engine is large, so that even though the same operation is performed by using the construction machinery, the amount of fuel consumed is considerably different for each operator.
In general, when construction equipment starts and begins to operate, an engine is driven at working revolutions per minute (RPM) (about 2,000 to 2,500 RPM), and when the operation is completed, that is, the operation is not continuously performed after a predetermined time from the completion time of the operation, the engine is driven at auto idle RPM (about 1,200 RPM).
When there is no separate operation for a front operation, a steering operation, and travelling for a predetermined time after the engine is driven at the auto idle RPM, it is determined that the engine is an idle state, and the auto idle RPM is decreased to an idle RPM (about 800 RPM), and as a result, the engine is minimally driven.
As described above, the construction machinery has a large difference in the amount of fuel consumed depending on the manipulation habit or an operation of equipment, so that it is necessary to induce an operator to operate the construction machinery with an efficient operation pattern. Accordingly, there is a device displaying a current operation load and operation fuel efficiency to an operator for promoting optimum fuel use and changing an operation pattern of an operator in an operation state.
However, there is no particular method of confirming, by an operator, fuel efficiency of an operation of the user currently performed with the construction machinery in comparison with fuel efficiency of a previous operation or an usual operation.